RE: Porsche spin-out (with no Alfa content)

[James Montebello <jamesm@domain.elided>]

This is drifting well off topic, but...

Drop-throttle oversteer isn't an inherent characteristic of fwd cars, nor
of nose-heavy cars, but of many cars of many types.  I've driven dozens
of cars, and transient handling characteristics can vary wildly from
car to car of a particular type.  Typically, very small differences like
shock and sway bar rates, or ride height, can make a bigger difference
than engine location.

For example: in my autocrossing days, I ran a '90 CRX Si.  This car
would oversteer very suddenly if you lifted mid-corner, frequently
uncatchably fast.  This was very unusual for a fwd car from my experience
up to that time.  However, another regular competitor had an '88 CRX
Si (outwardly very similar), and this car handled very differently.
Lifting mid-corner would rarely do more than cause tuck-in, or a mild
tail-out that could be easily caught.  However, the car also rolled a
great deal, and had less overall grip than my car, requiring very gentle
driving to keep it from sliding.  Yet another local CRX was an early '90
(mid '89 build date), which plowed heavily under nearly all conditions.
All three cars had subtly different rear suspension pickup points, and
all three of us ran a different front bar.  Just swapping the front bars
between the cars made a night and day difference, but the rear suspension
changes prevented them from handling identically even after the bar swap.

Other fwd cars I've had would only push, not matter what you did
(a certain Dodge Colt comes to mind).  Even hitting the brakes in
mid-corner would do little more than make it push straight off the road.
(Alfa content: my Berlina handles similarly).

A VW Golf, which had more roll than I liked but generally handled pretty
neutrally, one day started oversteering madly off-throttle.  Very puzzling
until I realized an oil-change tech had lowered the pressure in the rear
tires by only 5psi.  Huge difference from such an apparently small change.

IMHO, lifting when in trouble is a bad instinct to retain, no matter
the car.  Most cars, stock, are set up to understeer under power (fwd
cars can't really do anything else).  Many high-performance cars will
oversteer off the gas, some very badly, regardless of layout.  Back off
slowly, but never lift suddenly.  If you're sliding the front, you're
slowing down, and you'll quickly regain traction on dry pavement, and
the front will do what the steering is asking for.

james montebello


On Mon, 18 Mar 2002, Tony Sims wrote:

> One thing no one ever seems to mention during the "evil Porsche handling"
> discussions is that there's a much larger group of cars (driven by a much
> larger and likely less skilled group of drivers) that will show you a bad time
> if you get off the gas in the middle of a fast corner -- front wheel drive
> cars. A shunt is a shunt, which end went in the weeds first is academic once
> you're there.
> 
> The first front wheel drive car I ever drove was an early 80's Audi 4000.  I
> was hustling it over a very twisty local road that I drove regularly in my
> wanna-Bimmer Datsun 510 and my 2.8 Capri.  I went into a decreasing radius
> turn a little too hot and the front was drifting wide.  My instinct, honed in
> front engine, rear drive cars on often unpaved country roads, said "lift, let
> the nose tuck and the tail come out a bit, and then get back on the throttle
> and drift out clean".  My instincts learned a quick, expensive, and never
> forgotten lesson in physics and front-wheel car control, and I learned that
> Audi builds a pretty stout car.
> 
> The 911 is certainly a more likely candidate to generate enthusiast folklore
> than most front drive cars (rally fans please start your angry responses now),
> so I understand why the legend of trailing-throttle oversteer is known far and
> wide.  Still, it's an unkind blemish on the record of a truly remarkable car.
> I saw an article in EC or C&D recently where they drove a new Porsche and a
> vintage 911 back to back.  The tester commented specifically on how the older
> car was much more stable and easy to drive than he expected, given the
> "legend".
> 
> Tony
> Portland, OR
> 74 GTV
> 
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